Use custom download_url instead of torchvision's function

- importing torchvision is quiet timed consuming

git_helper.py

@@ -8,10 +8,34 @@
 import re
 import json
 import yaml
-from torchvision.datasets.utils import download_url
+import requests
 from tqdm.auto import tqdm
 from git.remote import RemoteProgress
 
+
+def download_url(url, dest_folder, filename=None):
+    # Ensure the destination folder exists
+    if not os.path.exists(dest_folder):
+        os.makedirs(dest_folder)
+
+    # Extract filename from URL if not provided
+    if filename is None:
+        filename = os.path.basename(url)
+
+    # Full path to save the file
+    dest_path = os.path.join(dest_folder, filename)
+
+    # Download the file
+    response = requests.get(url, stream=True)
+    if response.status_code == 200:
+        with open(dest_path, 'wb') as file:
+            for chunk in response.iter_content(chunk_size=1024):
+                if chunk:
+                    file.write(chunk)
+    else:
+        print(f"Failed to download file from {url}")
+
+
 config_path = os.path.join(os.path.dirname(__file__), "config.ini")
 nodelist_path = os.path.join(os.path.dirname(__file__), "custom-node-list.json")
 working_directory = os.getcwd()